This is happening on master.
Steps to reproduce(possibly)
1) Create a couple of pfs-masters inside another pfs like this by accident.
ie hammer pfs-master /usr/something
Receive a warning.
2) rm /usr/something
3) go to /pfs and create symlink to those PFSs you created above.
4) hammer pfs-destroy them
5) now create them properly: hammer pfs-master /pfs/something
6) Mount them
7) Run hammer cleanup
I get this
cleanup / - handle PFS #0 using /var/hammer/root
snapshots - skip
prune - skip
rebalance - skip
reblock - skip
recopy - skip
cleanup /var - handle PFS #1 using /var/hammer/var
snapshots - skip
prune - skip
rebalance - skip
reblock - skip
recopy - skip
cleanup /tmp - handle PFS #2 using /var/hammer/tmp
snapshots - disabled
prune - skip
rebalance - skip
reblock - skip
recopy - skip
cleanup /usr - handle PFS #3 using /var/hammer/usr
snapshots - skip
prune - skip
rebalance - skip
reblock - skip
recopy - skip
(null) - Segmentation fault (core dumped)
some hammer info:
Volume identification
Label ROOT
No. Volumes 1
FSID e308fe1f-e8c4-11de-a031-01215abc3429
HAMMER Version 4
Big block information
Total 106486
Used 545 (0.51%)
Reserved 69 (0.06%)
Free 105872 (99.42%)
Space information
No. Inodes 150802
Total size 832G (893269311488 bytes)
Used space 4.3G
Reserved space 552M
Free space 827G
PFS information
PFS-Id Mode Snaps Mounted-on
0 MASTER 1 /
1 MASTER 1 /var
2 MASTER 1 /tmp
3 MASTER 1 /usr
4 MASTER 1 /home
5 MASTER 1 /usr/obj
6 MASTER 1 /var/crash
7 MASTER 1 /var/tmp
8 MASTER 1 /usr/aubill
9 MASTER 1 /usr/pkg/pgsql
Petr